Brake mechanism for hoisting apparatus.



E. PAVELKA.

BRAKE MECHANISM FOR HOISTING APPARATUS.

APPLICATION FILED AUG.25. 1914.

1,163,169. Patented Dec. 7, 1915.

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Specification of Letters Patent.

Patented Dec. "Z, 1915.

Application filed August 25, 1914. Serial No. 858,452.

To all whom it may concern:

Be it known. that I, EDWARD PAVELKA, a

. citizen of the United States, residing in the specification.

:The invention relates to hand operated hoisting apparatus designed forlifting comparatively light loads, and is based upon Letters Patent toJohn A. Kearney, dated 1 May 19, 1914, No. 1,097,233.

The object of the invention is to provide means for reliably locking thedrive-shaft while the load is controlled by the brake a larger scale.

alone and thus prevent the accidental reengagement of the drive-shaftwith the winding-shaft and eliminate the danger of idle revolutions ofthe crank during the lowering operation.

Another object is to provide simple means conveniently located forholding the drive shaft in engagement with the winding-shaft andpreventing accidental release during the hoisting operation.

The invention consists in certain details of construction andarrangement by which the above objects are attained, to be hereinafterdescribed and claimed;

The accompanying drawings form a part of this specification and show theinvention as it has been carried out in practice.

Figure 1 is a side elevation of'the improved hoisting apparatus and aportion of the telescopic standard on which it is mounted. Fig. 2 is aplan view of the mechanism on Fig. 3 is a corresponding side elevationof a portion, partly in vertical section, the plane of section beingindicated by the broken line 33 in Fig. 2.

Fig. 4 is anelevation of portion showing the locking means, certainparts being in vertical section. Fig. 5 1s a front view of the lockingtooth alone, on a still larger scale.

Similar letters of reference indicate the same parts in all the figures.

A is a standard supporting a head B mounted upon the upper end thereofand forming part of an overhanging frame having two outwardly extendedarms B B in which are mounted two parallel horizontal shafts C and D,the former a relatively fixed windingshaft carried at the outer ends ofthe arms, and the latter an axially slidable drive-shaft -mountedbetween the winding shaft and head B. On the winding-shaft C isagearwheelC a winding-drum or spool C on which the hoisting cable M iswound, and a brake-drum C all fixed on the shaft C and revolvingtherewith. llhe drive-shaft D carries a pinion D fixed thereon adaptedto mesh -with the gearwheel G and is squared at one end a. receive thecrank F by which it may be revolved and correspondingly rotatethewinding-shaft. The shaft D ismounted toslide axially under certainconditions and is extended out: wardly at the end opposite to the crankto permit such endwise movement without escaping from its bearings inthe arms B B Partially encircling the brake-drum is a brake-band Eattached to a brake-lever G in such manner as to tighten the band whenthe lever is raised and thus grasp the brakedrum. Fixed on the shaft Dis a cone D lying normally adjacent to the brake-lever G which has anarm G extending beneath the cone to ahigh point on the latter, and asthe lever is raised to applythe brake the arm G acts onthe inclinedsurface of the ,cone and forces the latter with the shaft D to. moveaxially thussliding the teeth of the pinion D on those of the gearwheelC while still in mesh therewith until at the point at which the brakefriction is sufficient to hold the load, the teeth of the pinion aredisengaged completely from the gearwheel and the suspended load is heldby the brake alone; In this condition the load may be mounted on theframe at h and adapted to ride the teeth of the pinion B when the'latter is rotated in the direction to hoist,

and to engage theteethand hold the pinion against rotation in thedirection to lower.

The nose of the pawl is of such width as to maintain its engagement withthe pinion even when the latter is moved axially out of mesh as abovedescribed.

To insure against accidental or unintengrOQVQ d in such shaft.

tional endwise movement of theshaft during the hoisting operation alatch J 1s provided, pivoted on the exterior of the arm B at y andhaving a curved arm J partially encircling the shaft and having aportion J 2 adapted to engage in an annular The latch is convenientlylocated adjacent the brake-lever G and is raised to free the shaftbefore the application of the brake by depressing the thumb-plate J 3thereon, and the lifting movement is limited by the tailJ striking thehead of the bolt G on which the brakelever is pivoted, thus holding thelatch supported idly on the end of the shaft 'D during the shiftingmovement and in position to fall by gravity into engagement with thegroove cl when the latter is again presented thereto.

It has been found desirable to provide means for preventing the partialrengage- 'ment of the pinion and gearwheel during the lowering operationin order to avoid danger to the operator by the accidental revolutionsof the crank F liable to be thus induced. For this purpose a pin ortooth L is secured to the inner face of the arm 13 in position to beengagedbetween ad jacent teeth on the pinion D when the latter and itsshaft'D are moved axially to disengage the pinion and gearwheel, andthus- 7 lock the shaft D against rotation "in either rotation'until suchmovement is completed and the load held by the brake. When thedirection. The tooth L is shaped to match the space between adjacentteeth on the pin ion and'ex'tends close to the side face of the latterso that its engagement follows immediately upon the endwise movement ofthe shaft, and the mechanism is locked against pinion is freed from thegearwheel it is still locked and the drive-shaft and crank held againstrotation until the reengagement of the'pinion and gearwheel isagainfully established ready for another hoisting operation. The tooth Lis shown as having a base L secured to the inner face of the arm B butit will be understood it may be otherwise shaped and located. The formof the latch J may be varied and any suitable stop supplied thereforin'place of the bolt G I I claim I 1. In a hoisting apparatus, awindingshaft, a gearwheel and winding-drum fixed thereon, a brake deviceon said shaft, a lever for operating such brake device, an axially Islidable drive-shaft, a pinion fixed on said drive-shaft and arranged tomesh with said gearwheel, a cone fixed on said drive-shaft,

and means carried by said lever for engag ing said cone and moving saiddrive-shaft axially, thereby sliding said pinion out of mesh with saidgearwheel in the act of applying the brake,"andfixed means arranged toengage said pinion immediately after the initiation of such axialmovement and hold said pinion and drive-shaft against rotation.

2. In a hoisting apparatus, a winding shaft, a gearwheelandwinding-drumfixed thereon, a brake device on said shaft, a

. tiation of such axial movement and hold said pinion and drive-shaftagainst rotation.

3. In a hoisting apparatus, a windingshaft, a gearwheel andwinding-drumfixed thereon, a brake device on said shaft, a

lever for operating such brake device, an.

axially slidable drive-shaft having an annu lar groove therein, a pinionfixed on said drive-shaft and arranged to mesh with said gearwheel, acone fixed on said drive-shaft,

and means-carried by said lever for engaging said cone'and moving saiddrive-shaft axially, thereby sliding said pinion out of mesh with saidgearwheel in the act of applying the brake, a tooth fixedly mountedrelatively. to said pinion and arranged to be received between adjacentgear teeth. on

direction of the length of its shaft and a latch arranged to engage suchgroove and hold said drive-shaft against such axial movement untilreleased.

4. In a ho1st1ng apparatus, a frame having outwardly extending arms, awindingshaft mounted'in saidarms, a gearwheel and winding-drum fixed onsaid winding-shaft, a brake device on said winding-shaft, a brake-leveron one of said arms for operatingsaid brake device, an axially slidabledrive-shaft mounted in said arms and having an annular groove in one endexterior to one of said arms, a pinion fixed on said drive-shaft andarranged to mesh with said gearwheel, a cone fixed on said drive-shaft,

and means carried by said lever forengaging said cone and moving saiddrive-shaft axially, thereby sliding said pinion out of mesh with saidgearwheel in the'act of applying. the brake fixed means engageable withsaid pinion to hold the same against rotation, and means to hold saidpinion from sliding out of engagement with said means.

.5. In a hoisting apparatus, a frame having outwardly extending arms, awindingshaft mounted in said arms, a gearwheel and winding-drum fixed onsaid winding-shaft a brake device on said winding-shaft, a

"said pinion as the latter. is moved in the brake-lever on one of saidarms for operating said brake device, an axially slidable drive-shaftmounted in said arms and having an annular groove in one end exterior toone of said arms, a pinion fixed on said drive-shaft and arranged tomesh With said gearWheel, a cone fixed on said drive-shaft, and meanscarried by said lever for engaging said cone and moving said drive-shaftaxially, thereby sliding said pinion out of mesh with said gear-Wheel inthe act of applying the brake, a latch pivotally mounted on one of saidarms and arranged to fall by gravity into engagement With such grooveand hold said drive-shaft against such axial movement, means forlimiting the lifting release movement of said latch, and fixed means onthe other of said arms to be received between adjacent teeth on saidpinion as the latter is moved in the direction of the length of itsshaft.

In testimony that I claim the invention above set forth I afiix mysignature, in presence of two Witnesses.

EDWARD PAVELKA.

Witnesses: 7

CHARLES R. SEARLE, SOPHIE KEITEL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

